[AstroPy] How can I take the index of "True" value and minimum "True" in list with python ?

THƯỜNG Hoàng Đức hoangthuong.hust at gmail.com
Tue Apr 8 17:31:11 EDT 2014


HI Trey,

I wish you may understand. "You are tying to find the minimum of abs(E -
gE0) for every sub-array in gE0 ". It is not for every sub_array(for
diferent location in array).
 Firstly it have condition : abs(E - gE0) < 0.02. And after that I am
typing to take the closest value E-gE0 == 0 (It also is minimum) therefor
maybe some sub_arrays have not value. I am sorry, It is complicate to
understand. Hopefully you can help me.

I will show you a simple example:(The main ideal of my problem)

I have array ar = [1,8,9,10,100,101,102,1000,1001,1002,1003,5000]

I want to take I = [1,8,100,1000,5000] because 1 is alone and non value
follow. 8 is minimum of [8,9,10] and 8,9,10 is follow together.....

Thank you - Merci
Thuong


2014-04-08 18:45 GMT+02:00 Trey Wenger <tvw2pu at virginia.edu>:

> Hi again, Thuong.
>
> I think I understand what you are tying to do. You are tying to find the
> minimum of abs(E - gE0) for every sub-array in gE0. This is what I would do:
>
> min_indicies = [abs(E - my_gE0).argmin() for my_gE0 in gE0]
>
> So, min_indicies[0] is the index of the minimum of abs(E-gE0[0]),
> min_indicies[1] is the index of the minimum of abs(E - gE0[1]), etc.
>
> Hope this helps,
> Trey
>
>
>
> On Tue, Apr 8, 2014 at 12:20 PM, THƯỜNG Hoàng Đức <
> hoangthuong.hust at gmail.com> wrote:
>
>> thank you Trey,
>>
>> How can i find the minimum value for different location in the list. Let
>> me show you more detail: (I am sorry, it is long )
>>
>> I have:
>> In [15]: E
>> Out[15]:
>> array([  1.00000000e-03,   2.78255940e-03,   7.74263683e-03,
>>          2.15443469e-02,   5.99484250e-02,   1.66810054e-01,
>>          4.64158883e-01,   1.29154967e+00,   3.59381366e+00,
>>          1.00000000e+01])
>>
>> In [16]: gE0
>> Out[16]:
>> array([[  1.00000000e-03,   1.00000000e-03,   1.00000000e-03,
>>           1.00000000e-03,   1.00000000e-03,   1.00000000e-03,
>>           1.00000000e-03,   1.00000000e-03,   1.00000000e-03,
>>           1.00000000e-03],
>>        [  5.99484250e-03,   5.99484250e-03,   5.99484250e-03,
>>           5.99484250e-03,   5.99484250e-03,   5.99484250e-03,
>>           5.99484250e-03,   5.99484250e-03,   5.99484250e-03,
>>           5.99484250e-03],
>>        [  3.59381366e-02,   3.59381366e-02,   3.59381366e-02,
>>           3.59381366e-02,   3.59381366e-02,   3.59381366e-02,
>>           3.59381366e-02,   3.59381366e-02,   3.59381366e-02,
>>           3.59381366e-02],
>>        [  2.15443469e-01,   2.15443469e-01,   2.15443469e-01,
>>           2.15443469e-01,   2.15443469e-01,   2.15443469e-01,
>>           2.15443469e-01,   2.15443469e-01,   2.15443469e-01,
>>           2.15443469e-01],
>>        [  1.29154967e+00,   1.29154967e+00,   1.29154967e+00,
>>           1.29154967e+00,   1.29154967e+00,   1.29154967e+00,
>>           1.29154967e+00,   1.29154967e+00,   1.29154967e+00,
>>           1.29154967e+00],
>>        [  1.18292276e+00,   1.20239338e+00,   1.26419499e+00,
>>           1.38016526e+00,   1.57688572e+00,   1.91417885e+00,
>>           2.55149610e+00,   4.10977947e+00,   7.74263683e+00,
>>           7.74263683e+00],
>>        [  2.77831168e-01,   2.82126806e-01,   2.95703802e-01,
>>           3.20921794e-01,   3.62928377e-01,   4.32761236e-01,
>>           5.56895376e-01,   8.15796501e-01,   1.61701932e+00,
>>           4.64158883e+01],
>>        [  7.88832931e-02,   8.01002871e-02,   8.39462486e-02,
>>           9.10876310e-02,   1.02977169e-01,   1.22725700e-01,
>>           1.57778342e-01,   2.30672383e-01,   4.54431889e-01,
>>           2.78255940e+02],
>>        [  4.46767553e-02,   4.53659668e-02,   4.75440123e-02,
>>           5.15882797e-02,   5.83213761e-02,   6.95047231e-02,
>>           8.93535809e-02,   1.30626292e-01,   2.57284143e-01,
>>           1.66810054e+03],
>>        [  4.84949885e-02,   4.92431017e-02,   5.16072881e-02,
>>           5.59971873e-02,   6.33057070e-02,   7.54447993e-02,
>>           9.69899542e-02,   1.41789797e-01,   2.79271195e-01,
>>           1.00000000e+04]])
>>
>> In [25]: (abs(E - gE0) < 0.02)
>> Out[25]:
>> array([[ True,  True,  True, False, False, False, False, False, False,
>>         False],
>>        [ True,  True,  True,  True, False, False, False, False, False,
>>         False],
>>        [False, False, False,  True, False, False, False, False, False,
>>         False],
>>        [False, False, False, False, False, False, False, False, False,
>>         False],
>>        [False, False, False, False, False, False, False,  True, False,
>>         False],
>>        [False, False, False, False, False, False, False, False, False,
>>         False],
>>        [False, False, False, False, False, False, False, False, False,
>>         False],
>>        [False, False, False, False, False, False, False, False, False,
>>         False],
>>        [False, False, False, False,  True, False, False, False, False,
>>         False],
>>        [False, False, False, False,  True, False, False, False, False,
>>         False]], dtype=bool)
>>
>> In [26]: abs(E - gE0)
>> Out[26]:
>> array([[  0.00000000e+00,   1.78255940e-03,   6.74263683e-03,
>>           2.05443469e-02,   5.89484250e-02,   1.65810054e-01,
>>           4.63158883e-01,   1.29054967e+00,   3.59281366e+00,
>>           9.99900000e+00],
>>        [  4.99484250e-03,   3.21228310e-03,   1.74779432e-03,
>>           1.55495044e-02,   5.39535825e-02,   1.60815211e-01,
>>           4.58164041e-01,   1.28555482e+00,   3.58781882e+00,
>>           9.99400516e+00],
>>        [  3.49381366e-02,   3.31555772e-02,   2.81954998e-02,
>>           1.43937897e-02,   2.40102884e-02,   1.30871917e-01,
>>           4.28220747e-01,   1.25561153e+00,   3.55787553e+00,
>>           9.96406186e+00],
>>        [  2.14443469e-01,   2.12660910e-01,   2.07700832e-01,
>>           1.93899122e-01,   1.55495044e-01,   4.86334153e-02,
>>           2.48715414e-01,   1.07610620e+00,   3.37837019e+00,
>>           9.78455653e+00],
>>        [  1.29054967e+00,   1.28876711e+00,   1.28380703e+00,
>>           1.27000532e+00,   1.23160124e+00,   1.12473961e+00,
>>           8.27390782e-01,   1.33226763e-15,   2.30226400e+00,
>>           8.70845033e+00],
>>        [  1.18192276e+00,   1.19961082e+00,   1.25645235e+00,
>>           1.35862091e+00,   1.51693729e+00,   1.74736880e+00,
>>           2.08733721e+00,   2.81822980e+00,   4.14882316e+00,
>>           2.25736317e+00],
>>        [  2.76831168e-01,   2.79344246e-01,   2.87961166e-01,
>>           2.99377447e-01,   3.02979952e-01,   2.65951182e-01,
>>           9.27364927e-02,   4.75753164e-01,   1.97679434e+00,
>>           3.64158883e+01],
>>        [  7.78832931e-02,   7.73177277e-02,   7.62036117e-02,
>>           6.95432841e-02,   4.30287441e-02,   4.40843535e-02,
>>           3.06380541e-01,   1.06087728e+00,   3.13938177e+00,
>>           2.68255940e+02],
>>        [  4.36767553e-02,   4.25834074e-02,   3.98013755e-02,
>>           3.00439328e-02,   1.62704897e-03,   9.73053306e-02,
>>           3.74805302e-01,   1.16092337e+00,   3.33652952e+00,
>>           1.65810054e+03],
>>        [  4.74949885e-02,   4.64605423e-02,   4.38646513e-02,
>>           3.44528404e-02,   3.35728195e-03,   9.13652544e-02,
>>           3.67168929e-01,   1.14975987e+00,   3.31454247e+00,
>>           9.99000000e+03]])
>>
>> and Finaly:
>> At the first red line. I would to take the index[2] of value
>> 1.78255940e-03 (minimum)
>> At the second line. I would to take the index of value  1.74779432e-03
>> (minimum)
>> .
>> .
>> .
>>
>> May you try to help me
>>
>> Thuong,
>>
>>
>> 2014-04-08 16:09 GMT+02:00 Trey Wenger <tvw2pu at virginia.edu>:
>>
>>> Hi Thuong,
>>>
>>> I would do this
>>>
>>> index = abs(gE0[:,0] - ek).argmin()
>>>
>>> .argmin() returns the index at which the previous argument is smallest.
>>> Now, gE0[;,0][index] will be the value of gE0[;,0] closest to ek.
>>>
>>> For example,
>>>
>>> IPy> x = np.array([1.1, 2.3, 4.4])
>>> IPy> y = 2.2
>>> IPy> index = np.abs(x-y).argmin()
>>> IPy> index
>>> Out> 1
>>> IPy> x[index]
>>> Out> 2.3
>>> IPy> # this is the value in x closest to y
>>>
>>> Cheers,
>>> Trey
>>>
>>>
>>> On Tue, Apr 8, 2014 at 9:57 AM, THƯỜNG Hoàng Đức <
>>> hoangthuong.hust at gmail.com> wrote:
>>>
>>>> Dear AstroPyer,
>>>>
>>>> I have problem with ideals !
>>>> Firstly, I have two array. "ek" (one dimension - value in logspace) and
>>>> "gE0[]" (two dimension - value in logspace). After that I scan value ek in
>>>> array gE0 to find the equal value, It mean that abs(ek-gE0[:,0]) = 0. Due
>>>> to the numerical that in logspace, it can not equal zeros(There are some
>>>> point near the 0), and then I put the error for example err < 0.08 >>>>
>>>> abs(ek-gE0[:,0]) < 0.08. You can see the value below. The result I would to
>>>> take is True but it has several value < 0.08 also true, then how can i take
>>>> smallest if have several True.
>>>>
>>>>
>>>> In [53]: abs(ek-gE0[:,0]) < 0.08
>>>> Out[53]: array([False,  True, False, False, False, False,  True,
>>>> True,  True,  True], dtype=bool)
>>>>
>>>> ek = 0.1
>>>> In [52]: gE0[:,0]
>>>> Out[52]:
>>>> array([ 0.01      ,  0.04641589,  0.21544347,  1.        ,  1.93593016,
>>>>         0.51306049,  0.15479754,  0.06105322,  0.04410808,  0.04849499])
>>>>
>>>> How can i take only the value: i = 1, value = 0.04641589 and i = 9,
>>>> value = 0.04410808
>>>>
>>>>
>>>> Thankyou very muck
>>>>
>>>>  Merci beaucoup,
>>>>
>>>> Thuong
>>>>
>>>> ================================================
>>>> THUONG Hoang Duc
>>>>
>>>> Université des Sciences et des Technologies de Hanoi(USTH)
>>>> University of Science and Technology of Hanoi(USTH)
>>>> Hanoi University of Science and Technology (HUST)
>>>>
>>>> Email: hoangthuong.hust at gmail.com
>>>> Tel: +33 06 52 92 00 96
>>>> Tel: +84 01692887738
>>>>
>>>>
>>>> _______________________________________________
>>>> AstroPy mailing list
>>>> AstroPy at scipy.org
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>
>>>>
>>>
>>>
>>> --
>>> Trey V. Wenger
>>> Department of Astronomy
>>> University of Virginia
>>> http://www.astro.virginia.edu/~tvw2pu/
>>>
>>
>>
>>
>> --
>>
>> ================================================
>> THUONG Hoang Duc
>>
>> Université des Sciences et des Technologies de Hanoi(USTH)
>> University of Science and Technology of Hanoi(USTH)
>> Hanoi University of Science and Technology (HUST)
>>
>> Email: hoangthuong.hust at gmail.com
>> Tel: +33 06 52 92 00 96
>> Tel: +84 01692887738
>>
>>
>
>
> --
> Trey V. Wenger
> Department of Astronomy
> University of Virginia
> http://www.astro.virginia.edu/~tvw2pu/
>



-- 

================================================
THUONG Hoang Duc

Université des Sciences et des Technologies de Hanoi(USTH)
University of Science and Technology of Hanoi(USTH)
Hanoi University of Science and Technology (HUST)

Email: hoangthuong.hust at gmail.com
Tel: +33 06 52 92 00 96
Tel: +84 01692887738
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